…His [Baha’u’llah’s] reason for putting on the heavy
iron chains and for becoming the very embodiment of utter resignation and meekness,
was to lead every soul on earth to concord, to fellow‑feeling, to oneness; to
make known amongst all peoples the sign of the singleness of God, so that at
last the primal oneness deposited at the heart of all created things would bear
its destined fruit, and the splendour of ‘No
difference canst thou see in the creation of the God of Mercy,’ [Qur’án
67:3] would cast abroad its rays.
(‘Abdu’l-Baha,
‘Selections from the Writings of ‘Abdu’l-Baha’)